Steady state oscillations of circular currents in concentric polariton condensates

Concentric ring exciton polariton condensates emerging under non-resonant laser pump in an annular trapping potential support persistent circular currents of polaritons. The trapping potential is formed by a cylindrical micropillar etched in a semiconductor microcavity with embedded quantum wells and a repulsive cloud of optically excited excitons under the pump spot. The symmetry of the potential is subject to external control via manipulation by its pump-induced component. In the manuscript, we demonstrate excitation of concentric ring polariton current states with predetermined vorticity which we trace using interferometry measurements with a spherical reference wave. We also observe the polariton condensate dynamically changing its vorticity during observation, which results in pairs of fork-like dislocations on the time-averaged interferogram coexisting with azimuthally homogeneous photoluminescence distribution in the micropillar.

Automated summary

Concentric ring exciton polariton condensates are formed under non-resonant laser pump in an annular trapping potential. The symmetry of the potential can be controlled externally by manipulating its pump-induced component. By using interferometry measurements with a spherical reference wave, we can track the concentric ring polariton current states with predetermined vorticity, and observe the dynamic change of vorticity in the polariton condensate.